All space the private key in hexadecimal is located - keyspace:
FROM - 0000000000000000000000000000000000000000000000000000000000000001:
TO - FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF
No! This is a fallacy, these addresses (out of range) are only mirrored addresses (X / Y axis) Example:
fffffffffffffffffffffffffffffffebaaedce6af48a03bbfd25e8cd036418d -U -C
5Km2kuu7vtFDPpxywn4u3NLpbr5jKpTB3jsuDU2KYEqf3VKty2N - 1ESJVfV5UVERkWgVNfMjsLwJT88yMJHi8R - 1McVt1vMtCC7yn5b9wgX1833yCcLXzueeC
000000000000000000000000000000000000000000000000000000000000004c
5HpHagT65TZzG1PH3CSu63k8DbpvD8s5ip4nEB3kEsreKD614Nu - 1ESJVfV5UVERkWgVNfMjsLwJT88yMJHi8R - 1McVt1vMtCC7yn5b9wgX1833yCcLXzueeC
an address with two keys .. the same applies to your determined address:
"ucompressed" - 12M4QznuNZH2BRVbLK8SKvNqGTPJpCpST7
"compressed" - 1PRWyFKTsQSJaUdX9VKgQNw8JERPw2kMFm
All other addresses are in space
FROM - 0000000000000000000000000000000000000000000000000000000000000001:
TO - (FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF) - 5Km2kuu7vtFDPpxywn4u3NLu8iSdrqhxWT8tUKjeEXs2f9yxoWz No!

-> you cannot import these key in to the wallet!
"ucompressed" - 12M4QznuNZH2BRVbLK8SKvNqGTPJpCpST7
"compressed" - 1PRWyFKTsQSJaUdX9VKgQNw8JERPw2kMFm
000000000000000000000000000000014551231950b75fc4402da1732fc9bebe
(5HpHagT65TZzG1PH3CSu63kCkUBpkA7sBXKmV2m4wAt1vyA9SA4)